Abstract: Peri-implantitis is a chronic infectious disease that can affect peri-implant tissues such as gingiva and supporting bone, compromising the osseointegration prognosis. Photodynamic therapy is based on the principle that a photosensitizer can be activated by light of a suitable wavelength, producing singlet oxygen and other reactive agents which are extremely toxic to certain cells and bacteria. This article mainly elucidates light sources, photosensitizers and molecular mechanism involved in peri-implantitis treatment.

Key words: photodynamic therapy, photosensitizer, peri-implantitis